This application claims priority of Japanese Patent Application No. 2000-325206 filed on Oct. 25, 2000 and Japanese Patent Application No. 2000-333689 filed on Oct. 31, 2000, the complete disclosures of which are hereby incorporated by reference.
This invention relates to the field of a hot-stamping device for transferring a hot-stamping foil to a value-added medium.
An example of a conventional a hot-stamping device for transfer of holographic foil to a value-added medium, such as official documents and the like is the disclosure in International Patent Application WO95/04657. Here, documents becoming hot-stamping objects have a thickness and a width, for example, from single sheets to brochures. In said hot-stamping device, hot-stamping is performed on said documents by the following construction.
A large-size cam structure and a large-size motor are utilized so that a stamping at the load required for a hot-stamping can be effected in a stroke range corresponding to assumed thickness of the documents. Further, the construction is such that pressure greater than a required stamping load is applied, and excess stamping load is absorbed by a spring section built into a bottom stand. Further, a stamping stand and a load cam are arranged in a straight line so that rigidity of the entire device is high enough to withstand a large stamping load.
Hot-stamping device 301 shown in FIG. 23 is a device for transfer by a pressure application of a hot-stamping foil 303 such as holographic foil and the like to a value-added medium 302 such as tickets and cards of various kinds as well as official documents and the like, drive motor 305 drives cam 306 to rotate, a required load for hot-stamping acts on stamping section 304 to transfer hot-stamping foil 303 to a value-added medium 302 Further, in hot-stamping device 301, a load acting on stamping section 304 is a predetermined fixed load, uniform hot-stamping is thereby implemented. In hot-stamping device 301, when motor shaft 308 is locked when stamping section 304 comes in contact with object section 307 through value-added medium 302 and hot-stamping foil 303, an increase in electric current going through motor 305 is detected, and current through motor 305 is adjusted.
Next, although not a hot-stamping device, a bonding device disclosed in Japanese Laid-open Patent (Kokai) Hei 5-21529 uses a load cell to determine the value of applied pressure in the pressure application section. This value of applied pressure is compared to the predetermined value of applied pressure, and a pressure application section is activated so that the respective values of applied pressure are in agreement.
Nonetheless, in the conventional hot-stamping device, a load required for stamping is adequately obtainable from utilization of a large-size cam structure and large-size motor, but there are problems with such an increase in size of the device, an increase in manufacturing cost, and an increase in product weight.
Further, in a construction wherein an excess stamping load is absorbed by means of a spring section built in a bottom stand, there are cases where documents are bent or creased when there are changes in the position of a face acting as a stamping base. Further, because there is a repeated load application on a hard compression spring, it cannot be said that this a construction with long product life or high reliability. Moreover, because of inertial effect upon movement of the stamping stand, it is difficult to implement a continual stamping at a fixed load.
Further, although positioning a stamping stand and load cam in a straight line is effective from the standpoint of rigidity, there is the problem that the entire device becomes large in size. Further, in a hot-stamping device with a structure having such an arrangement, it becomes necessary to set the holographic foil by, as it were, stitching the various structural parts together; therefore, there is the problem that an exchange of holographic foil can only be done by skilled persons or professional service providers.
The pressure necessary for the transfer of a hot-stamping foil (for example, holographic foil and the like) varies with the kind of hot-stamping foil, further, permissible applied pressure varies with the kind of value-added medium (for example, ticket paper and plastic cards and the like) comprising the stamping object. In other words, the most suitable applied pressure that can transfer hot-stamping foil in satisfactory fashion, and which does not damage value-added medium, varies with the kind of hot-stamping foil and value-added medium.
However, in a hot-stamping device shown in FIG. 23, there is no way to control the application of stamping pressure appropriately, in response to the kind of hot-stamping foil and the kind of a value-added medium. In hot-stamping device 301 shown in FIG. 23, the relationship between the electric current in motor 305 and the load acting on stamping section 304 is not known, consequently, it is difficult to control application of stamping pressure accurately.
Therefore, as in a bonding device disclosed in Japanese Laid-open Patent (Kokai) Hei 5-21529, one thought is to use a load cell to measure the pressure-exerting load of the stamping section, compare this pressure-exerting load and the required fixed load, and operate the stamping section so the pressure-exerting load matches the fixed load, but when this control is utilized in the hot-stamping device without modification, the following problems are present.
In other words, when a stamping section is used in the one hot-stamping device constitutes a multiplicity of stamping sections with various respective sizes or when there is engraving on the stamping face, the area of the part in the stamping section that comes in contact with the value-added medium at the time of hot-stamping (hereinafter, termed stamping area in this specification) varies. Because of this, even when a fixed load is activated, the load generated per unit area in the stamping section at time of hot-stamping, in other words, pressure (hereinafter, termed stamping pressure in this specification) is not constant. In other words, even when a fixed load is activated, the stamping pressure is small in a stamping section with a large stamping area, the stamping pressure is large in stamping section with a small stamping area, so uniform hot-stamping cannot be implemented. Because of this, stamping pressure is weak and satisfactory transfer of hot-stamping foil does not occur. Alternatively, stamping pressure is too strong so there is concern of damage to the value-added medium and stamping section.
Therefore, this invention provides a hot-stamping device which, although small in size, is able to perform hot-stamping at a high speed and moreover in a satisfactory fashion at a stamping load adequate for a value-added medium having a thickness and width, furthermore, exchange of hot-stamping foil is performed easily.
Further, this invention provides a hot-stamping device and a stamping pressure control method for a hot-stamping device wherein regardless of how big or how small the size of the stamping section or the shape of stamping face, etc., uniform hot-stamping can be performed at an optimal stamping pressure.
To achieve the above, a hot-stamping device described has a stamping arm with one end being a free end, and stamping section positioned at said free end that applies pressure to a hot-stamping foil and a value-added medium to transfer a hot-stamping foil to a value-added medium, and a first cam in contact with a stamping arm to move a stamping section to close proximity of value-added medium, and a first drive section driving said the first cam, and a second cam bringing pressure-exerting load to bear on a stamping section moved to close proximity of the value-added medium, and a second drive section driving the second cam.
Consequently, a high-speed cam, in other words, the first cam used to move a stamping section, and a high-load cam, in other words, the second cam used to exert pressure on a stamping section, are used accordingly, and a stamping section is moved quickly to close proximity of a value-added medium by means of the first cam. The load for exerting pressure necessary for hot-stamping is generated by means of the second cam.
Further, in the invention a hot-stamping foil may comprise a hot-stamping foil tape, said hot-stamping foil tape is stored in cassette equipped with windup reel and sendout reel. Consequently, when there is changeover to a different hot-stamping foil tape, the task is easily performed by exchanging cassettes.
Further, in the invention a cassette may move to come in contact with value-added medium by means of the first cam drive. Consequently, a value-added medium is fixed, and shifting in a hot-stamping can be prevented. Further, when a hot-stamping foil tape is peeled off a value-added medium, floating of value-added medium is prevented.
Further, the invention may include a hot-stamping base position positioned where a cassette comes in contact with a value-added medium, a stamping section is moved to a base position by means of the first cam drive, at a base position, a load exerting pressure is brought to bear on a stamping section by means of the second cam drive. Consequently, a constant pressure-exerting load can be brought to bear continually at a level having no problems in practical use, even when the value-added medium has a thickness and a width.
To achieve such objectives, in a hot-stamping device having a stamping arm with one end being a free end, and a stamping section positioned at said free end to transfer hot-stamping foil to value-added medium, and a pressure application mechanism in contact with stamping arm to bring pressure-exerting load to bear on stamping section, and a drive section driving pressure application mechanism, a strain detection device is attached to a stamping arm, a stamping pressure of a stamping section at time of hot-stamping transfer is measured from an output of strain detection device, required amount of pressure application is obtained by comparing stamping pressure and predetermined target pressure, a required amount of pressure application is applied to the stamping section, and a drive section is controlled in this way.
Consequently, an amount of strain on a stamping arm may be detected by a strain detection device, a size of load generated in stamping section in response to this strain is obtained, this load is divided by a stamping area, a stamping pressure comprising load per unit area generated in the stamping section can be measured. By measuring a stamping pressure and adjusting a drive section so that stamping pressure matches target pressure comprising optimal pressure, obtained beforehand in accordance with hot-stamping foil and value-added medium, or is within the fixed range having target pressure as base, it is possible to effect a uniform hot-stamping at an optimal stamping pressure regardless of the size of the stamping area.
Further, a memory storage device to store stamping area of stamping section may be provided. Consequently, in the hot-stamping process, the user does not need to input a stamping area to measure a stamping pressure comprising load per unit area generated in the stamping section. Further, when a target pressure comprising an optimal pressure in accordance with hot-stamping foil and value-added medium is multiplied by a stamping area, a target load required to act on hot-stamping section can be obtained.
Further, in a stamping pressure control method for a hot-stamping device, a hot-stamping device having a stamping arm with one end being a free end, and a stamping section positioned at said free end to transfer a hot-stamping foil to a value-added medium, and a pressure application mechanism in contact with a stamping arm to bring pressure-exerting load to bear on a stamping section, and a drive section driving a pressure application mechanism, a strain detection device is attached to a stamping arm, a stamping load of a stamping section at time of a hot-stamping transfer is measured from an output of a strain detection device, a target load is obtained by multiplying predetermined target pressure by a stamping area of a stamping section, a required load is obtained by comparing stamping load and a target pressure, a required load is applied to a stamping section, thus, a drive section is controlled in this way.
Consequently, by detecting an amount of strain on a stamping arm by a strain detection device, measuring a stamping load generated in a stamping section in response to this strain, and adjusting a drive section so a stamping load matches target load or is within the fixed range having the target load as a base, it is possible to perform a uniform hot-stamping at an optimal stamping pressure regardless of the size of the stamping area.